1. Technical Field
The invention relates generally to a transmitter front-end, and more particularly, to a transmitter front-end with a sliced configuration.
2. Related Art
A transmitter front-end (TX FE) is an analog circuit within a transmitter/transceiver and lies between a digital circuit and an antenna of the transmitter/transceiver. In brief, the digital circuit generates a digital signal that is then converted by a digital-to-analog converter (DAC) into a baseband signal. The TX FE includes a local oscillator (LO) for generating a carrier signal, a mixer for mixing the baseband signal with the carrier signal to generate a radio frequency (RF) signal, and a gain stage for amplifying the RF signal. The amplified RF signal is then sent to, either directly or indirectly, the antenna for transmission.
A TX FE is sometimes designed to provide a large dynamic range. However, such a TX FE may face several problems. For example, it may suffer from noise degradation especially when it's providing a high gain. In addition, it may be unable to maintain its linearity at different gain levels. Furthermore, it may suffer from the so called “LO leakage” problem especially when it's providing a low gain. Moreover, it may be unable to reduce much of its power consumption even when it's providing a low gain.